std::basic_istringstream::basic_istringstream

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Input/output library

I/O manipulators

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

strstreambuf (deprecated)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

istrstream (deprecated)

ostrstream (deprecated)

strstream (deprecated)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

std::basic_istringstream

Member functions

basic_istringstream::basic_istringstream

basic_istringstream::operator=

basic_istringstream::swap

basic_istringstream::rdbuf

String operations

basic_istringstream::str

 

explicit basic_istringstream( ios_base::openmode mode = ios_base::in );	(1)
explicit basic_istringstream( const std::basic_string<CharT,Traits,Allocator>& str,                      ios_base::openmode mode = ios_base::in );	(2)
basic_istringstream( basic_istringstream&& other );	(3)	(since C++11)

Constructs new string stream.

1) Constructs new underlying string device. The underlying basic_stringbuf object is constructed as basic_stringbuf<Char,Traits,Allocator>(mode | ios_base::in).

2) Uses a copy of str as initial contents of the underlying string device. The underlying basic_stringbuf object is constructed as basic_stringbuf<Char,Traits,Allocator>(str, mode | ios_base::in).

3) Move constructor. Constructs the string stream with the state of other using move semantics.

Parameters

str	-	string to use as initial contents of the string stream
mode	-	specifies stream open mode. It is bitmask type, the following constants are defined: Constant Explanation app seek to the end of stream before each write binary open in binary mode in open for reading out open for writing trunc discard the contents of the stream when opening ate seek to the end of stream immediately after open
other	-	another string stream to use as source

Example

Run this code

#include <iostream>
#include <sstream>
int main()
{
    // default constructor (input/output stream)
    std::stringstream buf1;
    buf1 << 7;
    int n = 0;
    buf1 >> n;
    std::cout << "buf1 = " << buf1.str() << " n = " << n << '\n';
 
    // input stream
    std::istringstream inbuf("-10");
    inbuf >> n;
    std::cout << "n = " << n << '\n';
 
    // output stream in append mode (C++11)
    std::ostringstream buf2("test", std::ios_base::ate);
    buf2 << '1';
    std::cout << buf2.str() << '\n';
}

Output:

buf1 = 7 n = 7
n = -10
test1

See also

str	gets or sets the contents of underlying string device object (public member function)
(constructor)	constructs a basic_stringbuf object (public member function of std::basic_stringbuf)